JP2632874B2 - Decorative sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a decorative sheet that can be used for furniture, building materials, and the like, and more particularly to a decorative sheet excellent in surface hardness, scratch resistance, and the like.

[Conventional technology and problems]

Conventionally, base paper is impregnated with a thermoplastic resin, followed by patterning, and if necessary, a decorative sheet with a thermoplastic resin overcoat layer, or impregnated with thermoplastic resin after patterning on the base paper, A decorative sheet provided with an overcoat layer of a thermoplastic resin as necessary is known. However, in the former decorative sheet, since the pattern remains on the surface layer of the base paper, the pattern tends to fall off due to abrasion, and the surface hardness is poor. In the latter decorative sheet, the pattern penetrates into the base paper in order to apply the pattern before impregnation, and the pattern has good abrasion resistance, but has a problem of poor surface hardness and scratch performance.

Accordingly, an object of the present invention is to provide a decorative sheet which is free from patterns and has excellent surface hardness and scratch resistance.

[Means for solving the problem]

The decorative sheet of the present invention comprises: (i) base paper impregnated with a thermoplastic resin or a synthetic rubber alone or mixed; and (ii) (a) a glass transition temperature of 0 to 250 ° C. and a radical polymerizable unsaturated group. (B) ionizing radiation having a melting point of room temperature (20 ° C.) to 250 ° C., containing a compound having a radically polymerizable unsaturated group, and being solid and thermoplastic at room temperature in an uncured state And an overcoat layer obtained by crosslinking and curing the curable resin by ionizing radiation.

As base paper, cellulose fiber, rayon, vinylon,
Synthetic or semi-synthetic fibers such as polyester can be used alone or as a mixture and finished in a network with a normal paper machine. Further, titanium dioxide and various colorants can be added in order to increase the concealing property of the base paper and improve the design.

The thickness of the base paper is generally 23 g / m ² or more, but if it exceeds 150 g / m ² , the entire decorative sheet becomes too thick. Preferred thickness is 23~150g / m ^2. More preferably, it is 50 g / m ² or more.

As the ink for providing the pattern layer on the base paper, a conventionally known ink, for example, a coloring agent such as a dye or a pigment is added to an ink vehicle, and further, a plasticizer, a stabilizer, a wax, a grease, a drying agent, an auxiliary drying agent, and a curing agent. An ink obtained by arbitrarily adding additives such as an agent, a thickener, a dispersant, and a filler, and adding a solvent or a diluent and kneading sufficiently can be used.

Examples of the vehicle used in the above ink include various oils and fats such as linseed oil, soybean oil and synthetic drying oil, natural resins and processed resins such as rosin, copearl, dasoman, hardened rosin, rosin ester and polymerized rosin. Synthetic resins such as rosin-modified phenolic resin, 100% phenolic resin, maleic acid resin, alkyd resin, petroleum resin, vinyl resin, acrylic resin, polyamide resin, epoxy thread resin, amino alkyd resin,
Cellulose derivatives such as nitrocellulose, ethylcellulose and cellulose acetate, derivatives such as chlorinated rubber and cyclized rubber, glue, casein, dextrin, zein and the like can be used.

As a method for printing the above ink on base paper, a normal printing method such as a gravure printing method, a dry offset printing method, a letterpress printing method, a silk screen printing method can be used, and drawing is also acceptable.

As the impregnating resin that can be used in the present invention,
(A) thermoplastic resins such as acrylic-modified urethane, polyester-modified urethane, and other urethane resins; (b) acrylic acid esters such as SBR, NBR, and MBR as latex
A mixture of rubber-based resins such as above can be used alone or as a mixture.

The method for impregnating the base paper with the resin for impregnation includes a roll coating method, a gravure coating method, an air knife coating method, a reverse coating method, a dip coating method, a bar coating method, etc., and diluting each resin with an appropriate solvent. Impregnate as viscosity.

The main component of the topcoat is an ionizing radiation-curable resin that exhibits a thermoplastic solid state at room temperature even in an uncured state,
These include a polymer (1) having a glass transition temperature of 0 to 250 ° C having a radical polymerizable unsaturated group and a polymer (1) having a glass transition temperature of 0 to 250 ° C having a radical polymerizable unsaturated group. And a melting point having a radical polymerizable unsaturated group of 20 to
And a monomer compound (2) at 250 ° C.

(1) A polymer having a glass transition temperature of 0 to 250 ° C. and having a radically polymerizable unsaturated group.

Specifically, a compound obtained by polymerizing or copolymerizing the following compounds (1) to (4) is obtained by introducing a radical polymerizable unsaturated group by the methods (a) to (d) described below.

Monomers having a hydroxyl group: N-methylol (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2
-Hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate and the like.

Monomers having a carboxyl group: (meth) acrylic acid, (meth) acryloyloxyethyl monosuccinate and the like.

Monomer having epoxy group: glycidyl (meth) acrylate and the like.

Monomers having an aziridinyl group: 2-aziridinylethyl (meth) acrylate, allyl 2-aziridinylpropionate and the like.

Monomer having an amino group: (meth) acrylamide,
Diacetone (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and the like.

Monomers having a sulfone group: 2- (meth) acrylamido-2-methylpropanesulfonic acid and the like.

Monomer having an isocyanate group: an adduct of a diisocyanate and a radical polymerizable monomer having an active hydrogen such as a 1 mol to 1 mol adduct of 2,4-toluene diisocyanate and 2-hydroxyethyl (meth) acrylate etc.

In order to adjust the glass transition point or the physical properties of a cured film, the above compound is copolymerized with the following monomer copolymerizable with the compound.

Examples of such a copolymerizable monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and t-butyl (meth) acrylate. ) Acrylate, isoamyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and the like.

Next, by introducing a radically polymerizable unsaturated group into the polymer obtained from the above monomers by the following methods (a) to (d), an ultraviolet or electron beam curable resin is obtained.

(A) In the case of a polymer or copolymer of a monomer having a hydroxyl group or an amino group, a monomer having a carboxyl group of (meth) acrylic acid is subjected to a condensation reaction.

(B) In the case of a polymer or copolymer of a monomer having a carboxyl group or a sulfone group, the above-mentioned monomer having a hydroxyl group is subjected to a condensation reaction.

(C) In the case of a polymer or copolymer of a monomer having an epoxy group, an isocyanate group or an aziridinyl group, the above-mentioned monomer having a hydroxyl group or monomer having a carboxyl group is added.

(D) In the case of a polymer or copolymer of a monomer having a hydroxyl group or a carboxyl group, a monomer having an epoxy group, a monomer having an aziridinyl group, or a diisocyanate compound and a hydroxyl group-containing acrylate monomer The addition reaction is carried out with one to one mole of the adduct with the compound.

The above reaction is desirably carried out while adding a trace amount of a polymerization inhibitor such as hydroquinone and sending dry air.

(2) A compound having a melting point of room temperature (20 ° C.) to 250 ° C. and having a radical polymerizable unsaturated group.

Specific examples include stearyl (meth) acrylate, triacryl isocyanurate, cyclohexanediol diacrylate, cyclohexanediol di (meth) acrylate, spiroglycol diacrylate, spiroglycol (meth) acrylate, and the like.

In the present invention, the above (1) and (2) can be used as a mixture, and further, a radical polymerizable unsaturated monomer can be added thereto. This radically polymerizable unsaturated monomer increases the crosslink density upon irradiation with ionizing radiation and improves the heat resistance of the overcoat layer. In addition to the above-mentioned monomers, ethylene glycol di (meth) acrylate,
Polyethylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, Dipentaerythritol hexa (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, polyethylene glycol diglycidyl ether di (meth) acrylate, propylene glycol diglycidyl ether di (meth) acrylate, polypropylene glycol glycidyl ether di (meth) Acrylate, sorbitol tetraglycidyl ether tetra (meth) acrylate, etc. can be used. . The radical polymerizable unsaturated monomer is based on 100 parts by weight of the solid content of the copolymer mixture described above.
It is preferable to add 0.1 to 100 parts by weight.

The ionizing radiation-curable resin can be sufficiently cured by an electron beam. However, when the resin is cured by irradiation with ultraviolet light, acetylenic compounds such as acetophenones, benzophenones, Michler benzoyl benzoate, α-amido Roxy esters, tetramethylthiuram monosulfide, thioxanthones, and n-butylamine, triethylamine, tri-n-butylphosphine and the like as photosensitizers are mixed and used.

The thickness of the overcoat layer is 1 to 20μ before ionizing radiation curing.
m, and if it is less than 1 μm, the durability will be insufficient, and if it exceeds 20 μm, problems such as cracks will occur. The preferred thickness is 3 to 10 μm.

The decorative sheet of the present invention has an overcoat layer between the base paper on which the pattern is printed as required and the overcoat layer.

The role of the overcoat layer is to improve the adhesion with the impregnated overcoat layer, improve the physical properties such as abrasion resistance, etc. Covering the surface of the sheet with a resin provides surface smoothness and prevents penetration of the paint in the final overcoat layer.

To form the overcoat, for example, a resin as a main component, a desired additive is added to this, a transparent resin composition sufficiently kneaded with a solvent, for example, a roll coating method, a gravure coating method, a bar coating method, Air knife coating method, flow coating method, dip coating method, spray coating method or other usual coating method, or polyethylene, polypropylene, ethylene vinyl acetate,
A transparent resin such as polyester is coated using an extrusion coating method.

Examples of the above-mentioned transparent synthetic resin used for forming the overcoat layer using a normal coating method include natural resins and processed resins thereof, alkyd resins, butylated aminoaldehyde resins, phenol resins, and phthalic acid resins. Uses synthetic resins such as aminoplast resin, polyamide resin, vinyl resin, acrylic resin, epoxy resin, urethane resin, vinyl butyral resin, cellulose derivatives such as nitrocellulose, ethyl cellulose, cellulose acetate, and rubber derivatives. can do. Preferably, a resin having good adhesion to the impregnated resin, specifically, a resin of the same system as the impregnated resin is suitable.

The thickness of the overcoat layer is 1 μm to fulfill the above-mentioned role.
m or more is preferable, but if it exceeds 10 μm, an improvement in the effect corresponding thereto cannot be expected.

When imparting an embossing feeling to the decorative sheet, a matte pattern is formed on the overcoat layer. For the matte pattern, use the same paint as the above-mentioned top coat with the addition of extender pigments such as microsilica, calcium carbonate, clay, etc., and print by gravure printing, dry offset printing, letterpress printing, silk screen printing, etc. It can be formed by a method.
In particular, it is preferable that the matte pattern has a transparent feeling like the overcoat layer. Therefore, the embossing feeling becomes larger when the extender is also transparent and its refractive index is closer to the refractive index of the resin in the paint. The particle size is about 1 to 30 μm, preferably 2 to 10 μm, and the amount of addition is 1 to 30% by weight, preferably 3 to 10% by weight.

The thickness of the matte pattern is about 1 to 10 μm. If it is less than 1 μm, a sufficient embossing feeling cannot be obtained, and if it exceeds 10 μm, the corresponding effect cannot be improved. The preferred thickness is 3-5 μm.

Due to such a matte pattern, a part of the matte layer appears to be concave despite being actually raised. Therefore, by applying a matte pattern to the pattern on the base paper, the unevenness tuned to the pattern (tuned embossed feeling)
Is obtained.

When an ionizing radiation-curable resin is used for the overcoat layer or the resin layer for providing unevenness, curing is performed by irradiation with an electron beam or ultraviolet light.

For electron beam irradiation, Cockloft-Walton type, Bande graph type, Resonant transformer type, Insulated core transformer type, Linear type,
An electron beam having an energy in the range of 50 to 1000 KeV, preferably 100 to 300 KeV, emitted from various electron beam accelerators such as a dynamitron type and a high frequency type is used. In the case of ultraviolet irradiation, ultraviolet light emitted from an ultraviolet light source using a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc metal halide lamp, or the like is used.

〔Example〕

An embodiment of the decorative sheet of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a decorative sheet according to one embodiment of the present invention,
1 is a base paper, 2 is a picture layer, 3 is a resin-impregnated layer, and 4 is an overcoat layer. FIG. 2 shows a decorative sheet according to another embodiment of the present invention, wherein 1 to 4 are the same as in FIG. 1, 5 is a matte layer, and 6 is an overcoat layer. Matte layer 5 is picture layer 2
It is at the position corresponding to the picture inside.

Example A rubber obtained by printing a wood grain pattern on a surface of 80 g / m ² colored titanium paper (AX51 manufactured by Kojin Co., Ltd.) with a normal gravure ink using cellulose acetate as a vehicle, and then mixing SBR with an acrylate ester. Latex 25g / dry weight by impregnation equipment
m ² , and dried to obtain a resin-impregnated paper.

On top of this, a coating layer of a top coat (upimer manufactured by Mitsubishi Yuka Co., Ltd.) mainly containing triazine acrylate (ultraviolet curable resin: melting point 120 ° C.) is formed by solid printing, and 5% by weight of micro silica Was carried out by gravure printing using a triazine-based acrylate to which was added, and the top coat layer was cured by passing under an ozone-containing high-pressure mercury lamp (60 w / cm, 4 lamps) at 10 m / min.

The obtained decorative sheet was rich in surface hardness, scratch resistance, and abrasion resistance, and had a glossy pattern on the surface, and had an embossed feeling (a feeling of unevenness).

〔The invention's effect〕

The decorative sheet of the present invention has an excellent surface hardness, abrasion resistance, and abrasion resistance due to irradiation with ionizing radiation since the top coat layer made of the ionizing radiation-curable resin is formed on the surface. Further, when the overcoat layer is applied on the base paper on which the pattern is applied, not only the adhesion to the overcoat layer is further improved, but also the protection of the pattern is improved. Further, by applying a matte pattern to the surface of the overcoat layer, an embossed feeling rich in design can be imparted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a decorative sheet according to one embodiment of the present invention, and FIG. 2 is a sectional view showing a decorative sheet according to another embodiment of the present invention. 1 ... base paper 2 ... pattern layer 3 ... impregnated resin layer 4 ... overcoat layer 5 ... matte layer 6 ... overcoat layer

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-41040 (JP, A) JP-A-50-86571 (JP, A) JP-A-56-139958 (JP, A) 44828 (JP, Y2)

Claims (5)

(57) [Claims] 1. A base paper impregnated with (i) a thermoplastic resin or a synthetic rubber alone or as a mixture, and (ii) (a) a base paper having a glass transition temperature of 0 to 250 ° C. and having a radical polymerizable unsaturated group. Merging and / or (b) an ionizing radiation curing type having a melting point of room temperature (20 ° C.) to 250 ° C., containing a compound having a radical polymerizable unsaturated group, and being solid and thermoplastic at room temperature in an uncured state A decorative sheet having a top coat layer formed by crosslinking and curing a resin by ionizing radiation. 2. The decorative sheet according to claim 1, wherein a pattern is printed on said base paper. 3. The decorative sheet according to claim 1, wherein a matte pattern is formed on the overcoat layer. 4. The decorative sheet according to claim 3, wherein said matte pattern gives a sense of unevenness synchronized with a pattern on said base paper. 5. The decorative sheet according to claim 1, further comprising an overcoat layer between said base paper and said overcoat layer.